Transmission Speedo Port Plug Mopar

The B and M AUTOMOTIVE Transmission Speedo Port Plug for Mopar is a precision-engineered solution designed for mechanics and enthusiasts modifying classic and vintage Mopar transmissions. This aluminum port plug seals the speedometer cable port on the transmission tailhousing, making it essential when converting to electronic speedometer systems or when the original mechanical speedo output is no longer needed. Whether you're upgrading to modern instrumentation or simplifying your drivetrain during a resto-mod project, this component prevents fluid leakage and maintains transmission integrity at the port location.

Machined from durable aluminum and finished in black anodize, the transmission speedo port plug delivers corrosion resistance and a factory-correct appearance that complements stock or performance builds. The anodized coating protects against oxidation while the precision threading ensures a secure, leak-free seal without requiring tape or sealant—critical when containing automatic transmission fluid under pressure. B and M's attention to detail includes their logo marking the component, adding authenticity to your build. Hardware is included, simplifying installation and eliminating the need for separate fasteners or adapters.

This plug fits Mopar TorqueFlite 727 (TF-727), 36RH, 37RH, 46RH, and 47RH transmissions—the legendary powerplants found in Dodge, Plymouth, and Chrysler vehicles from the muscle car era through the 1990s. It's indispensable for builders swapping electronic speedometer clusters, installing modern gauge packages, or simply capping off unused transmission ports during rebuild and restoration. The compact 5.7 x 0.65 x 7.6 inch profile fits easily in tight engine bays, and at 0.24 lbs, adds negligible weight. Installation requires only basic hand tools and takes minutes, making it a smart upgrade for any Mopar transmission service or restomod project.